Automatic telephone system



July 19, 19320 G. zAPF ET AL AUTOMATIC TELEPHONE SYSTEM Filed Jan. 24. 1931 oe b om U 0 o Q n N G HAM. b MQ Amm, E XM i@ ,www w Nww. n. 7 Hw 0N .Se Q v H/PAT w? NMD kmmmwmu Innen l: s Eem-5 Zl'f Hlm Faisal-LEI" UNITED STATES PATET GEORG- ZAPF AND ALFONS PEISSNER, OF BERLIN, GERMANY, ASSIGNORS TO SIEMENS & HALSKE AKTIENGESELLSCHAFT, OF SIEMENSSTADT, NEAR BERLIN, GERMANY AUTOMATIC TELEPHONE SYSTEM Application led Jan-nary 24, 1931, Serial No. 510,895, and. in Germany May 1, 1930.

This invention relates to automatic telephone systems, in which connections of different value can be set up over the same connecting devices and lines.

In systems of this kind arrangements are commonly used whereby the switching over of the connecting devices for high value connections is e'liected by one or more auxiliary impulses succeeding the positioning impulses. In the case of connections extending over several junction lines isolated by repeaters there is the liability that the regular setting up of the desired connection may be disturbed by these auxiliary impulses, especially if they are repeated several times during the setting up of the connection.

The object of the invention is to remove this detect and to obtain a taultless reception and translation of the auxiliary impulses. According to the invention this is achieved in that to the impulse repeaters at the incoming end of a junction line are itted switchingr means, which, after switching-over has been eected at the repeater of the connection, by

' means of one or more auxiliary impulses render ineffective the further auxiliary impulses arriving` after every impulse train.

The accompanying single ligure of the drawing shows one method of carrying out the invention. Therein the trunk connection is of high value and the local connection is of low value. The latter has no special designation, but the former is designated by one auxiliary impulse. The setting up of a trunk connection will first be described. The circuits thatvare of no importance for the understanding of the invention are not shown.

The operator atthe switchboard position APL, who over a trunk line has been requested to call a particular subscriber, inserts her plug Sil into the jack K1 and so sends over the repeater U61 and the junction line VL a seizing impulse to the repeater U62. This is brought about in that when the plug Sil is inserted in the j ack K1 lirst of all the relay C1 at the repeater U61 is energized over: earth, plug S151, jack K1, winding of relay C1, battery, earth. Thereby the following operating circuit is established for relay A1 at the repeater U61: earth, contactsv 18s, 561, winding of relay A1, battery, earth. Relay A1 at its contacts 10ml and 12601 applies a source of alternatingcurrent to the speaking leads, and over the winding ot repeater U61 and the junction line VL it sends an impulse to the repeater U62. When operated, the relay C1 establishes a circuit for relay R over: earth, contact 861, winding of relay R, contact 23T, battery, earth. Relay R is operated and at contact 2311 removes the short circuit from the relay S. Thereupon relay S is operated and at contact 19s opens the circuit for winding I of relay A1. At repeater U62 is operated the alternating current relay J. Relay J closes its contact 43j to establish a circuit for relay A2 at repeater U62 earth, contact 41u, winding of relay A2, contact 43,7', battery, earth. Relay A2 is opera-ted and its contact 42h12 energizes the relay V. A circuit tor relay C2 is closed over: earth, contacts 47o, 48o and 46u. But relay C2 cannot be operated while relay A2 is energized because it is short circuited by contact 44a2. At the end of the seizing impulse the relay J and also relay A2 tall back, the latter opens its contact 44(12; relay C2 is operated in series with resistance "W and locks itself over contact 4562. As relay V falls back slowly after relay A2 has fallen back, a circuit :tor relay U is closed over: earth, contact 3662, contact 38o, winding of relay U, battery, earth. Relay U pulls up slowly but is at once short circuited again by contact 37o and falls back. During the seizing impulse the relay A2 also closes the contacts 33a2 and ifi-M2. As relay C2 is not energized during this time as betore described, the relay A3 at the succeeding final selector LIV is not energized over contact SM2. But contact 3462 applies steer# ing voltage to the lead b whereby the relay B3 at the group selector GW is energized, without, however, disturbing the setting up of the connection. At the repeater U62 only the relay C2 remains energized after the ending of the seizing impulse.

After inserting the plug Stl into the jack K1, the operator at the position APL throws her key AS. rThereby at the contacts ASI and ASllI she interrupts the line going to the plug S252, while the contacts ASII and ASIV connect her head set to the line going to the plug Stl. 0f the operators instrument there is only shown the contacts 2z', 311, in and 5a, which are operated by the number dial.

The operator now begins to dial by forwardly rotating the number dial. The contact 3a is opened and the contacts in and tm are closed as soon as the number dial leaves the normal position. Relay E is energized: earth, winding' I of relay E, contacts 5W., 4m, winding II of relay E, battery, earth. In addition, steering voltage is applied to the 5 lead for the entire duration of an impulse trainV and thus the relay B1 is energized at repeater U61: earth, contact 198, winding I of relay B1, lead 5, jack X1, plug S251, key ASIV, contact 4m., winding II of relay E, battery, earth. Relay B1 closes the following circuit: earth, contact 19s, winding II of relay B1, contacts 2151, 2251, winding of relay H, battery, earth. The relay H is actuated in this circuit; its method of functioning will be explained hereafter. Contact 1751 opens the circuit of winding II of relay A1 during the positioning impulse train. Contact 2051 prepares the circuit for the positioning impulses, which during the return motion of the dial pass over: earth, impulse contact 271, contact 1 6, key ASII, plug Stl, jack K1, lead 6 contact 2051, winding I of relay A1, battery, earth. Relay A1 responds to each impulse and repeats the positioning impulses to repeater U62 by applying alternating' current to the leads a and 5 over contacts 10a1 and 12a1 as when seizing impulses are transmitted.

Thereby at the repeater U62 the alternating` current relay J is operated at each impulse. Relay A2, which was energized in the same circuit as in the case of the seizing impulse. closes the already described circuit for relay V. Being slow-acting, the relay V holds up for the entire duration of the impulse train and the relay C2 does so likewise in a locking circuit although it is alternately short-circuited by Contact i462 during the im-V pulse train. Now relay U is also operated: earth, contact 3662, Contact 38o, winding of relay U, battery, earth. By opening its contacts u and 31u. the relay U interrupts the two speaking leads during the impulse train. Furthermore, it prepares a circuit for the auX- iliary impulse by closing the Contact 40u. By closing its contact 47@ the relay V keeps the operating circuit for relay A2 closed during the impulse train. Impulses to the succeeding group selector are transmitted over: earth, contacts 3662, 3362, lead a, contact 60p, winding of relay A3, battery, earth. During the impulse train the contact o applies steering voltage to the 5 lead, thereby keeping relay B3 at the group selector Gl/V energized over: earth, winding of relay B3, contact 6129, lead 5, contact 35e, battery, earth.

When the number dial at the operators position APL has run down, the contact 371. is closed and negative potential is applied to the lead a over contact 16 as relay E falls back slowly. At the same time the opening of contact 4m, causes steering voltage to be disconnected from the lead 5, whereupon relay B1 falls back. At repeater U61 relay B1 at contacts 2151 and 2251 removes the short circuit from its winding II and opens the circuit of relay H. As, however, relay H is a slow acting relay, it does not fall back until relay B1 has done so. Thus the following circuit is established: earth, contacts 19s, winding II of relay A1. contacts 1751, 14:5, lead a, jack K1, plug Sil, key ASII, contacts 16, 3a, winding of relay E, battery, earth. Relay A1 is operated in this circuit and sends an auxiliary impulse to repeater U62 in the manner already described. Thereupon at repeater U62 the relay J is again operated. By closing its contact 43,7' it establishes a circuit for relay T after relay V has fallen back, but relay U remains attracted as it is made slow acting and moreover has its winding short circuited by Contact 37o. The relay T is energized in the following circuit: earth, contacts 40u, 42?), winding I of relay T, contact l3j, battery, earth. Relay T places itself in a locking circuit over earth, Contact 3662, winding II of relay T, contact i, battery, earth. The impulse repeating relay A2 cannot be operated in this case, because the relay J has fallen back already when the relay U falls back and closes its contact 41u.

The further setting up of the connection at the succeeding group selector and final selector takes place in known manner. Therewith the contacts p an d 6179 are closed at the group selector GW. On the one hand they switch-through the speaking line and on the other hand disconnect the impulse receiving relay A3 and the steering relay B3 from the speaking line.

In the case of a trunk call, at the end of the impulses for positioning the final selector when the relay T at the repeater U62 has been energized, a circuit for relay X at the final selector LW and for relay Q at the repeater U62 is closed in position 3 of the side switch; earth, winding of relay X, position 3 of the side switch, lead a, wiper a of, the group selector GW, contact 60p, contacts 32a2, 51u. 5262, lt, windinO' of relay QQ, battery, earth. Relays Q and X are operated in this circuit. Relay X indicates at thel inal selector LI/V a trunk call designation, relay Q, sends a signalling impulse backwards to the operators position.

In the case of a local call the relay T at the repeater U62 is not energized because it gets through without any special auxiliary designating impulse, hence after the final selector has been positioned the following circuit is closed: earth, relay X, position 3 of the side switch, lead a, wiper a of the group selector GIV, contacts 60p, 32a2, 51u, 5262, winding of relay E, contact 53t, battery, earth. In this circuit is operated only the high resistance relay E at repeater U62. It again gives a signal impulse back to the operators position. The further circuit changes for setting up the connection do not concern the invention.

When the operator again rotates her number dial for transmitting another impulse train, the same circuit changes take place as for the transmission of the first impulse train. But the auxiliary impulse, which is again transmitted when contact 3a is closed upon the return of the number dial, does not have any eri'ect at the repeater U62 because relay T has its winding II in a locking circuit and the impulse transmitting relay A2 cannot be energized by an auxiliary impulse as relay V has already fallen back while relay U- is still energized as already described.

The connection is released by the operator at position APL withdrawing the plug S151. Relay C1 at repeater U61 falls back, so closing` the following circuit for relay A1: earth, contacts 19s, 701, winding I of relay A1, battery, earth. Relay A1 is operated in this circuit and by means of its contacts 10a1 and 12a1 it transmits a long releasing impulse to repeater U62. When relay C1 at repeater U61 falls back, the closing of contact 2401 short circuits relay R. Relay R falls back and by closing its contact 231 it short circuits the relay S. Both relays fall back slowly in succession. Relay S at contact 19s opens the circuit of Winding I of relay A1, which was closed during the release, and thus the releasing impulse is ended. At repeater U62 the relay J is again pulled up by the release impulse. Relay J energizes relay A2: earth, contact 41u, winding of relay A2, contact 43j, battery, earth. Relay A2 is operated and with its contact 14(2 short circuits relay C2 thus releasing it. At contact 3662 the relay C2 opens the locking circuit for winding II of relay T and at contact 5502 it opens the test circuit to group selector GIV.

In the example described the switching over of the junction lines is effected according` to the value, in this case for example for a trunk connection, by means of an auxiliary impulse, while for a low Value connection such as a local connection no auxiliary impulse is given. But the invention is not limited to this arrangement and it can be applied to systems in which the designation of the different values can be effected by several auxiliary impulses.

What is claimed is:

1. In a telephone system, an impulse repeater, a trunk line incoming to the repeater, a trunk line outgoing from the repeater, means for transmitting a series of similar current impulses over the incoming trunk line, and means in the repeater or repeating each impulse except the last of the series over the outgoing trunlr line.

2. In a telephone system, an impulse repeater, an incoming trunk line and an outgoing trunk line terminating in the repeater, means for transmitting a plurality of series of similar current impulses over the incoming trunk line, and means in the repeater for cancelling the last impulse and for repeating the remainder ofthe impulses of each series over the outgoing trunk line.

3. In a telephone system, an impulse repeater, an incoming trunk line and an outgoing trunk line terminating in the repeater, means for transmitting a plurality of series of similar current impulses over the incoming trunk line, means in the repeater for repeating all impulses except the last impulse of each series over the outgoing trunk line, and switching means in the repeater Aoperated by the last impulse of the` iirst series of impulses.

4. In a telephone system in which local and toll connections are established o-ver the same trunk lines and switching devices by transmitting series of impulses correspondingv to called numbers over a trunk line, and in which an additional impulse is transmitted over the vtrunk line after each series ofimpulses transmitted to establish a toll connection, means operated by an additional impulse for changing-over the switching devices for toll operation, and means responsive to the operation of said last means for rendering succeeding additional impulses ineffective.

5. In a telephone system in which connections of different values are established over the same trunk line and switching devices, means for transmitting series of impulses corresponding to the digits of called numbers over the trunk line, means for transmitting an additional impulse over the trunk line following each series of digit impulses transmitted to establish a. connection of a certain value, an impulse repeater associated with the trunk line for repeating the Vdigit impulses to the switching devices, switch-over means in the repeater operated responsive to the first of said additional impulses for adapting the repeater to operate in accordance with the value of the connection, means responsive to the operation of said switchover means for rendering the same independ- Cil ent of succeeding additional impulses, and means controlled by said switch-over means for adapting the switching devices to operate in accordance with the value of the connection.

6. In a telephone system in which connections of different values are set up over the same trunk line and switching devices by means of digit impulses transmitted over the trunk line and in which an additional impulse is transmitted over the trunk line after each digit transmitted to set up a connection of a certain value, a repeater associated with the trunk line for repeating the digit iml pulses to the switching devices, a relay in the repeater operated responsive to the receipt of the first additional impulse and locked for the duration of the connection, and means controlled by said relay for adapting the repeater to operate in a particular manner in accordance with the value of the connection.

7. In a telephone system, a repeater, incoming and outgoing trunk lines terminating in the repeater, an impulse receiving relay in the repeater, a switch-over relay in the repeater for adapting the repeater to operate in a particular manner in connections of a certain value, means for transmitting series of impulses corresponding to digits of called numbers over the incoming trunk line to operate said impulse receiving relay for establishing connections of different values, means for transmitting an additional impulse over the trunk line to operate said impulse receiving relay following each series of impulses transmitted to establish a connection of said certain value, means controlled by said impulse receiving relay for repeating the digit impulses over the outgoing trunk line, means controlled by the impulse relay for repeating the iirst additional impulse to said switchover relay to operate the same, and means controlled by said switch-over relay on operating for locking itself operated for the duration of the connection.

8, In a telephone system, a repeater, incoming and outgoing trunk lines terminating in the repeater, an impulse receiving relay in the repeater, a first slow relay controlled by said impulse receiving relay, a second slow relay controlled by said iirst slow relay, a switch-over relay for adapting the repeater to operate in a particular manner in connections of a certain value, means for transmitting series of digit impulses over the incoming trunk line to operate said impulse receiving relay for establishing connections of Ydifferent values, means for transmitting an additional impulse over the incoming trunk line to operate said impulse relay following each series of digit impulses transmitted to establish a connection of said certain value, means controlled by said impulse relay for repeating the digit impulses over said outgoing trunk line, means for operating said slow relays during the repeating of each series of impulses, means for releasing said slow relays in succession after the last digit impulse is repeated, a circuit for said switchover relay prepared responsive to the release of said first slow relay and prior to the release of said second slow relay, and means controlled by said impulse receiving relay in operating responsive to said additional impulse for completing said circuit to operate said switch-over relay.

9. In a telephone system, a repeater, incoming and outgoing talking conductors for the repeater, a double-wound impulse receiving relay for the repeater, means for transmitting a series of impulses corresponding to a digit of a called number followed by an additional impulse over an incoming talking conductor, means for connecting one winding of the relay to said talking conductor during the transmission of said series of impulses, means controlled by the relay for repeating the digit impulses over said outgoing talking conductors, means for connecting the other winding of said relay to said incoming talking conductor following the repeating of the last digit impulse of the series wherein said last means is reoperated to repeat the additional impulse over said outgoing talking conductors.

l0. In a telephone system, a trunk line including two talking conductors, a doublewound impulse receiving relay for the trunk line, means for transmitting a series of impulses of current of one polarity over one op said talking conductors, means for transmitting an impulse of current of a different polarity over said one conductor following the transmission of said series of impulses, means for connecting one winding of said relay to said one talking conductor during the transmission of said series of impulses, and means for connecting the other winding of said relay to said one talking' conductor during the transmission of said last impulse.

1l. In a telephone system, a trunk line connecting two exchanges and terminating in a repeater at each exchange, means in one repeater for receiving a series of direct current impulses and for transmitting a similar series of alternating current impulses over the trunk line, means in the other repeater for receiving said series of alternating current impulses and for transmitting to automatic switches a series of direct current impulses consisting of one impulse less than the number of impulses received, the impulse suppressed being in each case the last impulse of the series received.

l2. In a telephone system, an impulse repeater, a trunk line incoming to the repeater, a trunk line outgoing from the repeater` means for transmitting a series of impulses of alterating current over the incoming trunk line, and means in the repeater responsive 1n. and

to said impulses for transmitting an impulse of direct current over the outgoing trunk line for each of the incoming impulses eX- cept the last of the series.

In witness whereof, I hereunto subscribe my name this 23rd day of December, A. D.

GEORG ZAPF.

In Witness whereof, I hereunto subscribe 10 my name this 23rd day of December, A. D.

ALFONS PEISSNER. 

